Printing-paste.



UNITED STATES PATENT OFFICE.

JOSEPH DEINET, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBENFABRIKEN VORM. FRIEDR. BAYER 8c 00., OF ELBERFELD, GERMANY, A. CORPORATION OF GERMANY.

P INTING-Basin.

No Drawing.

Specification of Letters Patent. Patented Dec, 13, 1910. -Application filed April 29, 1909. Serial No.492,988.

To aZl whom it may concern:

Be it known that I, Josnrn DEINET, a citizen of the German Empire, residing at Elberfeld, Germany, have invented new and useful 7 Improvements in New Printing- Iastes, of which the following is a spec1- ficattbn.

I have made the surprising discovery that the dibenzoyl-l.8-diannnoanthraquinone can be used as a valuable dye for printing the textile fiber. It yields with reducing and thickening agentsya'luable' pastes which dye the fiber yellow shades of excellent fastness.

In order to carry out my invention, I proceed as follows, the parts being by Weight 100 parts of dibenzoyl-1.8-diaminoanthraquinone (10 per cent. paste consisting of 10% color and 90% water) are mixed with 74 parts of tragacanth thickening (65:1000). 1.1 parts of tincrystals, 7 parts of copperas powder, 8 parts of tartaric acid are added and the paste is well stirred. Print, run through soda lye (18 Be.) at 85, acidulate, rinse and soap at 00 C. A very fast clear yellow orange shade is thus obtained which remains unchanged upon boiling with 10% muriatic acid and remains also unchanged u. )on being touched with cold dilute and C()l( concentrated nitric acid and which upon being touched with a watery solution containing 0.4% of anhydrous hydrosulfite of sodium and 0.8% of caustic soda changes its color of yellow to rust-brown which on exposure to air assumes again its original ap earance. Other reducing agents 6. g. hydrosu fites may be used. V

I claim:

1. A printing paste comprising the leuco compound obtained by treating dibenzoyl- 1.8-diaminoanthraquinone with reducing agents in conjunction with thickening agents, characterized by producin on the fiber after oxidation a yellow sha e which remains unchanged upon boiling with 10% muriatic acid and remains also unchanged 'upon being touched with cold dilute and cold concentrated nitric acid and which upon being touched with a watery solution contaming 0.4% of anhydrous hydrosulfite of sodium and 0.8% of caustic soda changes its color of yellow to rust-brown which on ,exposure to air assumes again its original appearance, substantially as described.

2. A printing paste comprising the leuco compound obtained by treating dibenzoyl- 1.8-dian1inoanthraquinone with tin crystals,-

0.4% of anhydrous hydrosulfite of sodium and 0.8% of caustic soda changes its color of yellow to rust-l rown which on exposure to air assumes again its original appearance, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

O'rm Kiimo, C. J. l/Vmon'n, 

